Russell Henley hits out of the rough on the 18th hole during the third round of the Deutsche Bank Championship golf tournament in Norton, Mass., Sunday, Aug. 31, 2014. (AP Photo/Michael Dwyer)
(The Associated Press)

Chris Kirk reacts after missing an eagle putt on the 18th hole during the third round of the Deutsche Bank Championship golf tournament in Norton, Mass., Sunday, Aug. 31, 2014. (AP Photo/Michael Dwyer)
(The Associated Press)

Russell Henley either was playing down his chances or looking at Rory McIlroy's name high on the leaderboard in the Deutsche Bank Championship.

"Nobody is really expecting me to be sitting here right now," he said Sunday.

He was sitting atop a crowded leaderboard at the TPC Boston, which is becoming standard fare for these FedEx Cup playoffs. Henley ran off five birdies in a seven-hole stretch around the turn and added a late birdie for a 6-under 65.

That gave him a one-shot lead over Billy Horschel, who closed with three straight birdies for a 67.

Henley has won in each of his two seasons on the PGA Tour. He seems to win and then disappear for months at a time, though he is a serious threat when he gets around the lead. That means he's hitting the ball where he's aiming, and the 25-year-old from Georgia is as confident as anyone with the putter.

Even so, it was hard not to look over his shoulder.

McIlroy is the No. 1 player in the world after his back-to-back major wins, with a World Golf Championship sandwiched in between. The 25-year-old from Northern Ireland was so dialed in Sunday that he had birdie putts inside a foot on consecutive holes. He wound up with a 7-under 64 — same as his playing partner, the understated Chris Kirk — and was two shots behind. But this Labor Day finish appeared to be as wide open as last week at The Barclays.

Ten players were separated by only four shots. Five others, including Jordan Spieth and Rickie Fowler, were within five shots of the lead.

Here are five things to look for on Monday:

HENLEY HOPES: Henley won the Sony Open in his rookie debut on the PGA Tour last year. He didn't seriously contend again on tour until the Honda Classic, where he rallied from a two-shot deficit to McIlroy, and then won a four-man playoff that included McIlroy.

Henley has missed eight cuts and only twice has finished in the top 20 since then.

"I think I'm just still figuring it all out," Henley said. "I feel like I've been working really hard on my ball-striking to keep the ball more in front of me. I always feel pretty good with my putter. The other thing I have to work on is my attitude, and not be so hard on myself."

THE RORY FACTOR: McIlroy has had at least a share of the lead in seven of the last eight rounds of the majors, winning the British Open and the PGA Championship. Overlooked is how he rallied from three shots behind to win at Firestone.

His name — and recent play — can get anyone's attention.

"We all know what his ability is and what he can do on the golf course," Horschel said.

McIlroy said of his 64: "It feels normal. It feels like it's what I'm supposed to do."

EXPERIENCE FACTOR: Of the 10 players separated by four shots going into Monday, only McIlroy (1), Jason Day (7) and Keegan Bradley (24) are among the top 25 in the world ranking. But the others aren't' exactly lacking.

Six of them have won on the PGA Tour this season — Henley (Honda Classic), Kirk (McGladrey Classic), McIlroy (three times), Day (Match Play), Webb Simpson (Las Vegas) and Seung-yul Noh (New Orleans).

RYDER CUP: Monday is the final round before the Ryder Cup picks are announced. Luke Donald shot his second straight 74 and might have hurt his chances. Henley could give U.S. captain Tom Watson one more player to consider if he were to win, while Bradley, Simpson and Kirk might get his attention with even a high finish. And don't forget Ryan Palmer, who was four shots behind and might have gotten his bad round out of the way on Sunday.

Both captains get three wild-card picks.

MOVING ON: The top 70 in the FedEx Cup standings move on to the third playoff event next week at Cherry Hills for the BMW Championship.

Horschel was at No. 82 and appeared to be in good shape. Phil Mickelson was No. 57, and while he is 14 shots out of the lead, a solid round Monday should be enough to send Lefty back to the Denver course where he won the 1990 U.S. Amateur.

The long shot is now a medium shot. That would be Geoff Ogilvy, who barely got to Boston (by two points). Ogilvy started the week at No. 100, but when he made eagle on the final hole for a 65 on Sunday, he was only a couple of shots away from advancing to Denver.